Image width in email notification

Hello,
i use grafana for monitoring purposes with very good results but i would like improve the email alerts.
To be more specific i generate traffic graphs and i set thresholds to notify via email.
However the created image is too small and is not enough clear.
Is there any customization to encrease the image width?
Maybe have i to modify something inside alert_notification.html file ?
Regards

There is no option for this currently